xref: /freebsd/sys/dev/tpm/tpm.c (revision 3d265fce43746c293ae826e9603adbfe09f93cf6)
1 /*
2  * Copyright (c) 2008, 2009 Michael Shalayeff
3  * Copyright (c) 2009, 2010 Hans-Joerg Hoexer
4  * All rights reserved.
5  *
6  * Permission to use, copy, modify, and distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER IN
15  * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
16  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  */
18 
19 /* #define	TPM_DEBUG */
20 
21 #include <sys/cdefs.h>
22 __FBSDID("$FreeBSD$");
23 
24 #include <sys/param.h>
25 #include <sys/systm.h>
26 #include <sys/kernel.h>
27 #include <sys/malloc.h>
28 #include <sys/proc.h>
29 
30 #ifdef __FreeBSD__
31 #include <sys/module.h>
32 #include <sys/conf.h>
33 #include <sys/uio.h>
34 #include <sys/bus.h>
35 
36 #include <machine/bus.h>
37 #include <sys/rman.h>
38 #include <machine/resource.h>
39 
40 #include <machine/md_var.h>
41 
42 #include <isa/isareg.h>
43 #include <isa/isavar.h>
44 #else
45 #include <sys/device.h>
46 
47 #include <machine/cpu.h>
48 #include <machine/bus.h>
49 #include <machine/intr.h>
50 #include <machine/conf.h>
51 
52 #include <dev/isa/isareg.h>
53 #include <dev/isa/isavar.h>
54 #endif
55 #include <dev/tpm/tpmvar.h>
56 
57 #ifndef __FreeBSD__
58 /* XXX horrible hack for tcsd (-lpthread) workaround on OpenBSD */
59 #undef PCATCH
60 #define PCATCH	0
61 #endif
62 
63 #define	TPM_BUFSIZ	1024
64 
65 #define TPM_HDRSIZE	10
66 
67 #define TPM_PARAM_SIZE	0x0001
68 
69 #ifdef __FreeBSD__
70 #define IRQUNK	-1
71 #endif
72 
73 #define	TPM_ACCESS			0x0000	/* access register */
74 #define	TPM_ACCESS_ESTABLISHMENT	0x01	/* establishment */
75 #define	TPM_ACCESS_REQUEST_USE		0x02	/* request using locality */
76 #define	TPM_ACCESS_REQUEST_PENDING	0x04	/* pending request */
77 #define	TPM_ACCESS_SEIZE		0x08	/* request locality seize */
78 #define	TPM_ACCESS_SEIZED		0x10	/* locality has been seized */
79 #define	TPM_ACCESS_ACTIVE_LOCALITY	0x20	/* locality is active */
80 #define	TPM_ACCESS_VALID		0x80	/* bits are valid */
81 #define	TPM_ACCESS_BITS	\
82     "\020\01EST\02REQ\03PEND\04SEIZE\05SEIZED\06ACT\010VALID"
83 
84 #define	TPM_INTERRUPT_ENABLE	0x0008
85 #define	TPM_GLOBAL_INT_ENABLE	0x80000000	/* enable ints */
86 #define	TPM_CMD_READY_INT	0x00000080	/* cmd ready enable */
87 #define	TPM_INT_EDGE_FALLING	0x00000018
88 #define	TPM_INT_EDGE_RISING	0x00000010
89 #define	TPM_INT_LEVEL_LOW	0x00000008
90 #define	TPM_INT_LEVEL_HIGH	0x00000000
91 #define	TPM_LOCALITY_CHANGE_INT	0x00000004	/* locality change enable */
92 #define	TPM_STS_VALID_INT	0x00000002	/* int on TPM_STS_VALID is set */
93 #define	TPM_DATA_AVAIL_INT	0x00000001	/* int on TPM_STS_DATA_AVAIL is set */
94 #define	TPM_INTERRUPT_ENABLE_BITS \
95     "\020\040ENA\010RDY\03LOCH\02STSV\01DRDY"
96 
97 #define	TPM_INT_VECTOR		0x000c	/* 8 bit reg for 4 bit irq vector */
98 #define	TPM_INT_STATUS		0x0010	/* bits are & 0x87 from TPM_INTERRUPT_ENABLE */
99 
100 #define	TPM_INTF_CAPABILITIES		0x0014	/* capability register */
101 #define	TPM_INTF_BURST_COUNT_STATIC	0x0100	/* TPM_STS_BMASK static */
102 #define	TPM_INTF_CMD_READY_INT		0x0080	/* int on ready supported */
103 #define	TPM_INTF_INT_EDGE_FALLING	0x0040	/* falling edge ints supported */
104 #define	TPM_INTF_INT_EDGE_RISING	0x0020	/* rising edge ints supported */
105 #define	TPM_INTF_INT_LEVEL_LOW		0x0010	/* level-low ints supported */
106 #define	TPM_INTF_INT_LEVEL_HIGH		0x0008	/* level-high ints supported */
107 #define	TPM_INTF_LOCALITY_CHANGE_INT	0x0004	/* locality-change int (mb 1) */
108 #define	TPM_INTF_STS_VALID_INT		0x0002	/* TPM_STS_VALID int supported */
109 #define	TPM_INTF_DATA_AVAIL_INT		0x0001	/* TPM_STS_DATA_AVAIL int supported (mb 1) */
110 #define	TPM_CAPSREQ \
111   (TPM_INTF_DATA_AVAIL_INT|TPM_INTF_LOCALITY_CHANGE_INT|TPM_INTF_INT_LEVEL_LOW)
112 #define	TPM_CAPBITS \
113   "\020\01IDRDY\02ISTSV\03ILOCH\04IHIGH\05ILOW\06IEDGE\07IFALL\010IRDY\011BCST"
114 
115 #define	TPM_STS			0x0018		/* status register */
116 #define TPM_STS_MASK		0x000000ff	/* status bits */
117 #define	TPM_STS_BMASK		0x00ffff00	/* ro io burst size */
118 #define	TPM_STS_VALID		0x00000080	/* ro other bits are valid */
119 #define	TPM_STS_CMD_READY	0x00000040	/* rw chip/signal ready */
120 #define	TPM_STS_GO		0x00000020	/* wo start the command */
121 #define	TPM_STS_DATA_AVAIL	0x00000010	/* ro data available */
122 #define	TPM_STS_DATA_EXPECT	0x00000008	/* ro more data to be written */
123 #define	TPM_STS_RESP_RETRY	0x00000002	/* wo resend the response */
124 #define	TPM_STS_BITS	"\020\010VALID\07RDY\06GO\05DRDY\04EXPECT\02RETRY"
125 
126 #define	TPM_DATA	0x0024
127 #define	TPM_ID		0x0f00
128 #define	TPM_REV		0x0f04
129 #define	TPM_SIZE	0x5000		/* five pages of the above */
130 
131 #define	TPM_ACCESS_TMO	2000		/* 2sec */
132 #define	TPM_READY_TMO	2000		/* 2sec */
133 #define	TPM_READ_TMO	120000		/* 2 minutes */
134 #define TPM_BURST_TMO	2000		/* 2sec */
135 
136 #define	TPM_LEGACY_BUSY	0x01
137 #define	TPM_LEGACY_ABRT	0x01
138 #define	TPM_LEGACY_DA	0x02
139 #define	TPM_LEGACY_RE	0x04
140 #define	TPM_LEGACY_LAST	0x04
141 #define	TPM_LEGACY_BITS	"\020\01BUSY\2DA\3RE\4LAST"
142 #define	TPM_LEGACY_TMO		(2*60)	/* sec */
143 #define	TPM_LEGACY_SLEEP	5	/* ticks */
144 #define	TPM_LEGACY_DELAY	100
145 
146 /* Set when enabling legacy interface in host bridge. */
147 int tpm_enabled;
148 
149 #ifdef __FreeBSD__
150 #define	TPMSOFTC(dev) \
151 	((struct tpm_softc *)dev->si_drv1)
152 
153 d_open_t	tpmopen;
154 d_close_t	tpmclose;
155 d_read_t	tpmread;
156 d_write_t	tpmwrite;
157 d_ioctl_t	tpmioctl;
158 
159 static struct cdevsw tpm_cdevsw = {
160 	.d_version =	D_VERSION,
161 	.d_flags =	D_NEEDGIANT,
162 	.d_open =	tpmopen,
163 	.d_close =	tpmclose,
164 	.d_read =	tpmread,
165 	.d_write =	tpmwrite,
166 	.d_ioctl =	tpmioctl,
167 	.d_name =	"tpm",
168 };
169 #else
170 #define	TPMSOFTC(dev) \
171     (struct tpm_softc *)device_lookup(&tpm_cd, minor(dev))
172 
173 struct cfdriver tpm_cd = {
174 	NULL, "tpm", DV_DULL
175 };
176 
177 int	tpm_match(device_t , void *, void *);
178 void	tpm_attach(device_t , device_t , void *);
179 
180 struct cfattach tpm_ca = {
181 	sizeof(struct tpm_softc), tpm_match, tpm_attach
182 };
183 #endif
184 
185 const struct {
186 	u_int32_t devid;
187 	char name[32];
188 	int flags;
189 #define TPM_DEV_NOINTS	0x0001
190 } tpm_devs[] = {
191 	{ 0x000615d1, "IFX SLD 9630 TT 1.1", 0 },
192 	{ 0x000b15d1, "IFX SLB 9635 TT 1.2", 0 },
193 	{ 0x100214e4, "Broadcom BCM0102", TPM_DEV_NOINTS },
194 	{ 0x00fe1050, "WEC WPCT200", 0 },
195 	{ 0x687119fa, "SNS SSX35", 0 },
196 	{ 0x2e4d5453, "STM ST19WP18", 0 },
197 	{ 0x32021114, "ATML 97SC3203", TPM_DEV_NOINTS },
198 	{ 0x10408086, "INTEL INTC0102", 0 },
199 	{ 0, "", TPM_DEV_NOINTS },
200 };
201 
202 int tpm_tis12_irqinit(struct tpm_softc *, int, int);
203 int tpm_tis12_init(struct tpm_softc *, int, const char *);
204 int tpm_tis12_start(struct tpm_softc *, int);
205 int tpm_tis12_read(struct tpm_softc *, void *, int, size_t *, int);
206 int tpm_tis12_write(struct tpm_softc *, void *, int);
207 int tpm_tis12_end(struct tpm_softc *, int, int);
208 
209 #ifdef __FreeBSD__
210 void tpm_intr(void *);
211 #else
212 int tpm_intr(void *);
213 void tpm_powerhook(int, void *);
214 int tpm_suspend(struct tpm_softc *, int);
215 int tpm_resume(struct tpm_softc *, int);
216 #endif
217 
218 int tpm_waitfor_poll(struct tpm_softc *, u_int8_t, int, void *);
219 int tpm_waitfor_int(struct tpm_softc *, u_int8_t, int, void *, int);
220 int tpm_waitfor(struct tpm_softc *, u_int8_t, int, void *);
221 int tpm_request_locality(struct tpm_softc *, int);
222 int tpm_getburst(struct tpm_softc *);
223 u_int8_t tpm_status(struct tpm_softc *);
224 int tpm_tmotohz(int);
225 
226 int tpm_legacy_probe(bus_space_tag_t, bus_addr_t);
227 int tpm_legacy_init(struct tpm_softc *, int, const char *);
228 int tpm_legacy_start(struct tpm_softc *, int);
229 int tpm_legacy_read(struct tpm_softc *, void *, int, size_t *, int);
230 int tpm_legacy_write(struct tpm_softc *, void *, int);
231 int tpm_legacy_end(struct tpm_softc *, int, int);
232 
233 #ifdef __FreeBSD__
234 
235 /*
236  * FreeBSD specific code for probing and attaching TPM to device tree.
237  */
238 #if 0
239 static void
240 tpm_identify(driver_t *driver, device_t parent)
241 {
242 	BUS_ADD_CHILD(parent, ISA_ORDER_SPECULATIVE, "tpm", 0);
243 }
244 #endif
245 
246 int
247 tpm_attach(device_t dev)
248 {
249 	struct tpm_softc *sc = device_get_softc(dev);
250 	int irq;
251 
252 	sc->mem_rid = 0;
253 	sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &sc->mem_rid,
254 	    RF_ACTIVE);
255 	if (sc->mem_res == NULL)
256 		return ENXIO;
257 
258 	sc->sc_bt = rman_get_bustag(sc->mem_res);
259 	sc->sc_bh = rman_get_bushandle(sc->mem_res);
260 
261 	sc->irq_rid = 0;
262 	sc->irq_res = bus_alloc_resource_any(dev, SYS_RES_IRQ, &sc->irq_rid,
263 	    RF_ACTIVE | RF_SHAREABLE);
264 	if (sc->irq_res != NULL)
265 		irq = rman_get_start(sc->irq_res);
266 	else
267 		irq = IRQUNK;
268 
269 	/* In case PnP probe this may contain some initialization. */
270 	tpm_tis12_probe(sc->sc_bt, sc->sc_bh);
271 
272 	if (tpm_legacy_probe(sc->sc_bt, sc->sc_bh)) {
273 		sc->sc_init = tpm_legacy_init;
274 		sc->sc_start = tpm_legacy_start;
275 		sc->sc_read = tpm_legacy_read;
276 		sc->sc_write = tpm_legacy_write;
277 		sc->sc_end = tpm_legacy_end;
278 	} else {
279 		sc->sc_init = tpm_tis12_init;
280 		sc->sc_start = tpm_tis12_start;
281 		sc->sc_read = tpm_tis12_read;
282 		sc->sc_write = tpm_tis12_write;
283 		sc->sc_end = tpm_tis12_end;
284 	}
285 
286 	printf("%s", device_get_name(dev));
287 	if ((sc->sc_init)(sc, irq, "tpm")) {
288 		tpm_detach(dev);
289 		return ENXIO;
290 	}
291 
292 	if (sc->sc_init == tpm_tis12_init && sc->irq_res != NULL &&
293 	    bus_setup_intr(dev, sc->irq_res, INTR_TYPE_TTY, NULL,
294 	    tpm_intr, sc, &sc->intr_cookie) != 0) {
295 		tpm_detach(dev);
296 		printf(": cannot establish interrupt\n");
297 		return 1;
298 	}
299 
300 	sc->sc_cdev = make_dev(&tpm_cdevsw, device_get_unit(dev),
301 			    UID_ROOT, GID_WHEEL, 0600, "tpm");
302 	sc->sc_cdev->si_drv1 = sc;
303 
304 	return 0;
305 }
306 
307 int
308 tpm_detach(device_t dev)
309 {
310 	struct tpm_softc * sc = device_get_softc(dev);
311 
312 	if(sc->intr_cookie){
313 		bus_teardown_intr(dev, sc->irq_res, sc->intr_cookie);
314 	}
315 
316 	if(sc->mem_res){
317 		bus_release_resource(dev, SYS_RES_MEMORY,
318 				     sc->mem_rid, sc->mem_res);
319 	}
320 
321 	if(sc->irq_res){
322 		bus_release_resource(dev, SYS_RES_IRQ,
323 				     sc->irq_rid, sc->irq_res);
324 	}
325 	if(sc->sc_cdev){
326 		destroy_dev(sc->sc_cdev);
327 	}
328 
329 	return 0;
330 }
331 
332 #else
333 /*
334  * OpenBSD specific code for probing and attaching TPM to device tree.
335  */
336 int
337 tpm_match(device_t parent, void *match, void *aux)
338 {
339 	struct isa_attach_args *ia = aux;
340 	struct cfdata *cf = match;
341 	bus_space_tag_t bt = ia->ia_memt;
342 	bus_space_handle_t bh;
343 	int rv;
344 
345 	/* There can be only one. */
346 	if (cf->cf_unit)
347 		return 0;
348 
349 	if (tpm_legacy_probe(ia->ia_iot, ia->ia_iobase)) {
350 		ia->ia_iosize = 2;
351 		return 1;
352 	}
353 
354 	if (ia->ia_maddr == -1)
355 		return 0;
356 
357 	if (bus_space_map(bt, ia->ia_maddr, TPM_SIZE, 0, &bh))
358 		return 0;
359 
360 	if ((rv = tpm_tis12_probe(bt, bh))) {
361 		ia->ia_iosize = 0;
362 		ia->ia_msize = TPM_SIZE;
363 	}
364 
365 	bus_space_unmap(bt, bh, TPM_SIZE);
366 	return rv;
367 }
368 
369 void
370 tpm_attach(device_t parent, device_t self, void *aux)
371 {
372 	struct tpm_softc *sc = (struct tpm_softc *)self;
373 	struct isa_attach_args *ia = aux;
374 	bus_addr_t iobase;
375 	bus_size_t size;
376 	int rv;
377 
378 	if (tpm_legacy_probe(ia->ia_iot, ia->ia_iobase)) {
379 		sc->sc_bt = ia->ia_iot;
380 		iobase = ia->ia_iobase;
381 		size = ia->ia_iosize;
382 		sc->sc_batm = ia->ia_iot;
383 		sc->sc_init = tpm_legacy_init;
384 		sc->sc_start = tpm_legacy_start;
385 		sc->sc_read = tpm_legacy_read;
386 		sc->sc_write = tpm_legacy_write;
387 		sc->sc_end = tpm_legacy_end;
388 	} else {
389 		sc->sc_bt = ia->ia_memt;
390 		iobase = ia->ia_maddr;
391 		size = TPM_SIZE;
392 		sc->sc_init = tpm_tis12_init;
393 		sc->sc_start = tpm_tis12_start;
394 		sc->sc_read = tpm_tis12_read;
395 		sc->sc_write = tpm_tis12_write;
396 		sc->sc_end = tpm_tis12_end;
397 	}
398 
399 	if (bus_space_map(sc->sc_bt, iobase, size, 0, &sc->sc_bh)) {
400 		printf(": cannot map registers\n");
401 		return;
402 	}
403 
404 	if ((rv = (sc->sc_init)(sc, ia->ia_irq, sc->sc_dev.dv_xname))) {
405 		bus_space_unmap(sc->sc_bt, sc->sc_bh, size);
406 		return;
407 	}
408 
409 	/*
410 	 * Only setup interrupt handler when we have a vector and the
411 	 * chip is TIS 1.2 compliant.
412 	 */
413 	if (sc->sc_init == tpm_tis12_init && ia->ia_irq != IRQUNK &&
414 	    (sc->sc_ih = isa_intr_establish(ia->ia_ic, ia->ia_irq, IST_EDGE,
415 	    IPL_TTY, tpm_intr, sc, sc->sc_dev.dv_xname)) == NULL) {
416 		bus_space_unmap(sc->sc_bt, sc->sc_bh, TPM_SIZE);
417 		printf("%s: cannot establish interrupt\n",
418 		    sc->sc_dev.dv_xname);
419 		return;
420 	}
421 
422 	sc->sc_suspend = PWR_RESUME;
423 	sc->sc_powerhook = powerhook_establish(tpm_powerhook, sc);
424 }
425 #endif
426 
427 /* Probe TPM using TIS 1.2 interface. */
428 int
429 tpm_tis12_probe(bus_space_tag_t bt, bus_space_handle_t bh)
430 {
431 	u_int32_t r;
432 	u_int8_t save, reg;
433 
434 	r = bus_space_read_4(bt, bh, TPM_INTF_CAPABILITIES);
435 	if (r == 0xffffffff)
436 		return 0;
437 
438 #ifdef TPM_DEBUG
439 	printf("tpm: caps=%b\n", r, TPM_CAPBITS);
440 #endif
441 	if ((r & TPM_CAPSREQ) != TPM_CAPSREQ ||
442 	    !(r & (TPM_INTF_INT_EDGE_RISING | TPM_INTF_INT_LEVEL_LOW))) {
443 #ifdef TPM_DEBUG
444 		printf("tpm: caps too low (caps=%b)\n", r, TPM_CAPBITS);
445 #endif
446 		return 0;
447 	}
448 
449 	save = bus_space_read_1(bt, bh, TPM_ACCESS);
450 	bus_space_write_1(bt, bh, TPM_ACCESS, TPM_ACCESS_REQUEST_USE);
451 	reg = bus_space_read_1(bt, bh, TPM_ACCESS);
452 	if ((reg & TPM_ACCESS_VALID) && (reg & TPM_ACCESS_ACTIVE_LOCALITY) &&
453 	    bus_space_read_4(bt, bh, TPM_ID) != 0xffffffff)
454 		return 1;
455 
456 	bus_space_write_1(bt, bh, TPM_ACCESS, save);
457 	return 0;
458 }
459 
460 /*
461  * Setup interrupt vector if one is provided and interrupts are know to
462  * work on that particular chip.
463  */
464 int
465 tpm_tis12_irqinit(struct tpm_softc *sc, int irq, int idx)
466 {
467 	u_int32_t r;
468 
469 	if ((irq == IRQUNK) || (tpm_devs[idx].flags & TPM_DEV_NOINTS)) {
470 		sc->sc_vector = IRQUNK;
471 		return 0;
472 	}
473 
474 	/* Ack and disable all interrupts. */
475 	bus_space_write_4(sc->sc_bt, sc->sc_bh, TPM_INTERRUPT_ENABLE,
476 	    bus_space_read_4(sc->sc_bt, sc->sc_bh, TPM_INTERRUPT_ENABLE) &
477 	    ~TPM_GLOBAL_INT_ENABLE);
478 	bus_space_write_4(sc->sc_bt, sc->sc_bh, TPM_INT_STATUS,
479 	    bus_space_read_4(sc->sc_bt, sc->sc_bh, TPM_INT_STATUS));
480 
481 	/* Program interrupt vector. */
482 	bus_space_write_1(sc->sc_bt, sc->sc_bh, TPM_INT_VECTOR, irq);
483 	sc->sc_vector = irq;
484 
485 	/* Program interrupt type. */
486 	if (sc->sc_capabilities & TPM_INTF_INT_EDGE_RISING)
487 		r = TPM_INT_EDGE_RISING;
488 	else if (sc->sc_capabilities & TPM_INTF_INT_LEVEL_HIGH)
489 		r = TPM_INT_LEVEL_HIGH;
490 	else
491 		r = TPM_INT_LEVEL_LOW;
492 	bus_space_write_4(sc->sc_bt, sc->sc_bh, TPM_INTERRUPT_ENABLE, r);
493 
494 	return 0;
495 }
496 
497 /* Setup TPM using TIS 1.2 interface. */
498 int
499 tpm_tis12_init(struct tpm_softc *sc, int irq, const char *name)
500 {
501 	u_int32_t r;
502 	int i;
503 
504 	r = bus_space_read_4(sc->sc_bt, sc->sc_bh, TPM_INTF_CAPABILITIES);
505 #ifdef TPM_DEBUG
506 	printf(" caps=%b ", r, TPM_CAPBITS);
507 #endif
508 	if ((r & TPM_CAPSREQ) != TPM_CAPSREQ ||
509 	    !(r & (TPM_INTF_INT_EDGE_RISING | TPM_INTF_INT_LEVEL_LOW))) {
510 		printf(": capabilities too low (caps=%b)\n", r, TPM_CAPBITS);
511 		return 1;
512 	}
513 	sc->sc_capabilities = r;
514 
515 	sc->sc_devid = bus_space_read_4(sc->sc_bt, sc->sc_bh, TPM_ID);
516 	sc->sc_rev = bus_space_read_1(sc->sc_bt, sc->sc_bh, TPM_REV);
517 
518 	for (i = 0; tpm_devs[i].devid; i++)
519 		if (tpm_devs[i].devid == sc->sc_devid)
520 			break;
521 
522 	if (tpm_devs[i].devid)
523 		printf(": %s rev 0x%x\n", tpm_devs[i].name, sc->sc_rev);
524 	else
525 		printf(": device 0x%08x rev 0x%x\n", sc->sc_devid, sc->sc_rev);
526 
527 	if (tpm_tis12_irqinit(sc, irq, i))
528 		return 1;
529 
530 	if (tpm_request_locality(sc, 0))
531 		return 1;
532 
533 	/* Abort whatever it thought it was doing. */
534 	bus_space_write_1(sc->sc_bt, sc->sc_bh, TPM_STS, TPM_STS_CMD_READY);
535 
536 	return 0;
537 }
538 
539 int
540 tpm_request_locality(struct tpm_softc *sc, int l)
541 {
542 	u_int32_t r;
543 	int to, rv;
544 
545 	if (l != 0)
546 		return EINVAL;
547 
548 	if ((bus_space_read_1(sc->sc_bt, sc->sc_bh, TPM_ACCESS) &
549 	    (TPM_ACCESS_VALID | TPM_ACCESS_ACTIVE_LOCALITY)) ==
550 	    (TPM_ACCESS_VALID | TPM_ACCESS_ACTIVE_LOCALITY))
551 		return 0;
552 
553 	bus_space_write_1(sc->sc_bt, sc->sc_bh, TPM_ACCESS,
554 	    TPM_ACCESS_REQUEST_USE);
555 
556 	to = tpm_tmotohz(TPM_ACCESS_TMO);
557 
558 	while ((r = bus_space_read_1(sc->sc_bt, sc->sc_bh, TPM_ACCESS) &
559 	    (TPM_ACCESS_VALID | TPM_ACCESS_ACTIVE_LOCALITY)) !=
560 	    (TPM_ACCESS_VALID | TPM_ACCESS_ACTIVE_LOCALITY) && to--) {
561 		rv = tsleep(sc->sc_init, PRIBIO | PCATCH, "tpm_locality", 1);
562 		if (rv &&  rv != EWOULDBLOCK) {
563 #ifdef TPM_DEBUG
564 			printf("tpm_request_locality: interrupted %d\n", rv);
565 #endif
566 			return rv;
567 		}
568 	}
569 
570 	if ((r & (TPM_ACCESS_VALID | TPM_ACCESS_ACTIVE_LOCALITY)) !=
571 	    (TPM_ACCESS_VALID | TPM_ACCESS_ACTIVE_LOCALITY)) {
572 #ifdef TPM_DEBUG
573 		printf("tpm_request_locality: access %b\n", r, TPM_ACCESS_BITS);
574 #endif
575 		return EBUSY;
576 	}
577 
578 	return 0;
579 }
580 
581 int
582 tpm_getburst(struct tpm_softc *sc)
583 {
584 	int burst, to, rv;
585 
586 	to = tpm_tmotohz(TPM_BURST_TMO);
587 
588 	burst = 0;
589 	while (burst == 0 && to--) {
590 		/*
591 		 * Burst count has to be read from bits 8 to 23 without
592 		 * touching any other bits, eg. the actual status bits 0
593 		 * to 7.
594 		 */
595 		burst = bus_space_read_1(sc->sc_bt, sc->sc_bh, TPM_STS + 1);
596 		burst |= bus_space_read_1(sc->sc_bt, sc->sc_bh, TPM_STS + 2)
597 		    << 8;
598 #ifdef TPM_DEBUG
599 		printf("tpm_getburst: read %d\n", burst);
600 #endif
601 		if (burst)
602 			return burst;
603 
604 		rv = tsleep(sc, PRIBIO | PCATCH, "tpm_getburst", 1);
605 		if (rv && rv != EWOULDBLOCK) {
606 			return 0;
607 		}
608 	}
609 
610 	return 0;
611 }
612 
613 u_int8_t
614 tpm_status(struct tpm_softc *sc)
615 {
616 	u_int8_t status;
617 
618 	status = bus_space_read_1(sc->sc_bt, sc->sc_bh, TPM_STS) &
619 	    TPM_STS_MASK;
620 
621 	return status;
622 }
623 
624 int
625 tpm_tmotohz(int tmo)
626 {
627 	struct timeval tv;
628 
629 	tv.tv_sec = tmo / 1000;
630 	tv.tv_usec = 1000 * (tmo % 1000);
631 
632 	return tvtohz(&tv);
633 }
634 
635 /* Save TPM state on suspend. */
636 int
637 #ifdef __FreeBSD__
638 tpm_suspend(device_t dev)
639 #else
640 tpm_suspend(struct tpm_softc *sc, int why)
641 #endif
642 {
643 #ifdef __FreeBSD__
644 	struct tpm_softc *sc = device_get_softc(dev);
645 	int why = 1;
646 #endif
647 	u_int8_t command[] = {
648 	    0, 193,		/* TPM_TAG_RQU_COMMAND */
649 	    0, 0, 0, 10,	/* Length in bytes */
650 	    0, 0, 0, 156	/* TPM_ORD_SaveStates */
651 	};
652 
653 	/*
654 	 * Power down:  We have to issue the SaveStates command.
655 	 */
656 	sc->sc_write(sc, &command, sizeof(command));
657 	sc->sc_read(sc, &command, sizeof(command), NULL, TPM_HDRSIZE);
658 #ifdef TPM_DEBUG
659 	printf("tpm_suspend: power down: %d -> %d\n", sc->sc_suspend, why);
660 #endif
661 	sc->sc_suspend = why;
662 
663 	return 0;
664 }
665 
666 /*
667  * Handle resume event.  Actually nothing to do as the BIOS is supposed
668  * to restore the previously saved state.
669  */
670 int
671 #ifdef __FreeBSD__
672 tpm_resume(device_t dev)
673 #else
674 tpm_resume(struct tpm_softc *sc, int why)
675 #endif
676 {
677 #ifdef __FreeBSD__
678 	struct tpm_softc *sc = device_get_softc(dev);
679 	int why = 0;
680 #endif
681 #ifdef TPM_DEBUG
682 	printf("tpm_resume: resume: %d -> %d\n", sc->sc_suspend, why);
683 #endif
684 	sc->sc_suspend = why;
685 
686 	return 0;
687 }
688 
689 /* Dispatch suspend and resume events. */
690 #ifndef __FreeBSD__
691 void
692 tpm_powerhook(int why, void *self)
693 {
694 	struct tpm_softc *sc = (struct tpm_softc *)self;
695 
696 	if (why != PWR_RESUME)
697 		tpm_suspend(sc, why);
698 	else
699 		tpm_resume(sc, why);
700 }
701 #endif	/* !__FreeBSD__ */
702 
703 /* Wait for given status bits using polling. */
704 int
705 tpm_waitfor_poll(struct tpm_softc *sc, u_int8_t mask, int tmo, void *c)
706 {
707 	int rv;
708 
709 	/*
710 	 * Poll until either the requested condition or a time out is
711 	 * met.
712 	 */
713 	while (((sc->sc_stat = tpm_status(sc)) & mask) != mask && tmo--) {
714 		rv = tsleep(c, PRIBIO | PCATCH, "tpm_poll", 1);
715 		if (rv && rv != EWOULDBLOCK) {
716 #ifdef TPM_DEBUG
717 			printf("tpm_waitfor_poll: interrupted %d\n", rv);
718 #endif
719 			return rv;
720 		}
721 	}
722 
723 	return 0;
724 }
725 
726 /* Wait for given status bits using interrupts. */
727 int
728 tpm_waitfor_int(struct tpm_softc *sc, u_int8_t mask, int tmo, void *c,
729     int inttype)
730 {
731 	int rv, to;
732 
733 	/* Poll and return when condition is already met. */
734 	sc->sc_stat = tpm_status(sc);
735 	if ((sc->sc_stat & mask) == mask)
736 		return 0;
737 
738 	/*
739 	 * Enable interrupt on tpm chip.  Note that interrupts on our
740 	 * level (SPL_TTY) are disabled (see tpm{read,write} et al) and
741 	 * will not be delivered to the cpu until we call tsleep(9) below.
742 	 */
743 	bus_space_write_4(sc->sc_bt, sc->sc_bh, TPM_INTERRUPT_ENABLE,
744 	    bus_space_read_4(sc->sc_bt, sc->sc_bh, TPM_INTERRUPT_ENABLE) |
745 	    inttype);
746 	bus_space_write_4(sc->sc_bt, sc->sc_bh, TPM_INTERRUPT_ENABLE,
747 	    bus_space_read_4(sc->sc_bt, sc->sc_bh, TPM_INTERRUPT_ENABLE) |
748 	    TPM_GLOBAL_INT_ENABLE);
749 
750 	/*
751 	 * Poll once more to remedy the race between previous polling
752 	 * and enabling interrupts on the tpm chip.
753 	 */
754 	sc->sc_stat = tpm_status(sc);
755 	if ((sc->sc_stat & mask) == mask) {
756 		rv = 0;
757 		goto out;
758 	}
759 
760 	to = tpm_tmotohz(tmo);
761 #ifdef TPM_DEBUG
762 	printf("tpm_waitfor_int: sleeping for %d ticks on %p\n", to, c);
763 #endif
764 	/*
765 	 * tsleep(9) enables interrupts on the cpu and returns after
766 	 * wake up with interrupts disabled again.  Note that interrupts
767 	 * generated by the tpm chip while being at SPL_TTY are not lost
768 	 * but held and delivered as soon as the cpu goes below SPL_TTY.
769 	 */
770 	rv = tsleep(c, PRIBIO | PCATCH, "tpm_intr", to);
771 
772 	sc->sc_stat = tpm_status(sc);
773 #ifdef TPM_DEBUG
774 	printf("tpm_waitfor_int: woke up with rv %d stat %b\n", rv,
775 	    sc->sc_stat, TPM_STS_BITS);
776 #endif
777 	if ((sc->sc_stat & mask) == mask)
778 		rv = 0;
779 
780 	/* Disable interrupts on tpm chip again. */
781 out:	bus_space_write_4(sc->sc_bt, sc->sc_bh, TPM_INTERRUPT_ENABLE,
782 	    bus_space_read_4(sc->sc_bt, sc->sc_bh, TPM_INTERRUPT_ENABLE) &
783 	    ~TPM_GLOBAL_INT_ENABLE);
784 	bus_space_write_4(sc->sc_bt, sc->sc_bh, TPM_INTERRUPT_ENABLE,
785 	    bus_space_read_4(sc->sc_bt, sc->sc_bh, TPM_INTERRUPT_ENABLE) &
786 	    ~inttype);
787 
788 	return rv;
789 }
790 
791 /*
792  * Wait on given status bits, uses interrupts where possible, otherwise polls.
793  */
794 int
795 tpm_waitfor(struct tpm_softc *sc, u_int8_t b0, int tmo, void *c)
796 {
797 	u_int8_t b;
798 	int re, to, rv;
799 
800 #ifdef TPM_DEBUG
801 	printf("tpm_waitfor: b0 %b\n", b0, TPM_STS_BITS);
802 #endif
803 
804 	/*
805 	 * If possible, use interrupts, otherwise poll.
806 	 *
807 	 * We use interrupts for TPM_STS_VALID and TPM_STS_DATA_AVAIL (if
808 	 * the tpm chips supports them) as waiting for those can take
809 	 * really long.  The other TPM_STS* are not needed very often
810 	 * so we do not support them.
811 	 */
812 	if (sc->sc_vector != IRQUNK) {
813 		b = b0;
814 
815 		/*
816 		 * Wait for data ready.  This interrupt only occurs
817 		 * when both TPM_STS_VALID and TPM_STS_DATA_AVAIL are asserted.
818 		 * Thus we don't have to bother with TPM_STS_VALID
819 		 * separately and can just return.
820 		 *
821 		 * This only holds for interrupts!  When using polling
822 		 * both flags have to be waited for, see below.
823 		 */
824 		if ((b & TPM_STS_DATA_AVAIL) && (sc->sc_capabilities &
825 		    TPM_INTF_DATA_AVAIL_INT))
826 			return tpm_waitfor_int(sc, b, tmo, c,
827 			    TPM_DATA_AVAIL_INT);
828 
829 		/* Wait for status valid bit. */
830 		if ((b & TPM_STS_VALID) && (sc->sc_capabilities &
831 		    TPM_INTF_STS_VALID_INT)) {
832 			rv = tpm_waitfor_int(sc, b, tmo, c, TPM_STS_VALID_INT);
833 			if (rv != 0)
834 				return rv;
835 			else
836 				b = b0 & ~TPM_STS_VALID;
837 		}
838 
839 		/*
840 		 * When all flags are taken care of, return.  Otherwise
841 		 * use polling for eg. TPM_STS_CMD_READY.
842 		 */
843 		if (b == 0)
844 			return 0;
845 	}
846 
847 	re = 3;
848 restart:
849 	/*
850 	 * If requested wait for TPM_STS_VALID before dealing with
851 	 * any other flag.  Eg. when both TPM_STS_DATA_AVAIL and TPM_STS_VALID
852 	 * are requested, wait for the latter first.
853 	 */
854 	b = b0;
855 	if (b0 & TPM_STS_VALID)
856 		b = TPM_STS_VALID;
857 
858 	to = tpm_tmotohz(tmo);
859 again:
860 	if ((rv = tpm_waitfor_poll(sc, b, to, c)) != 0)
861 		return rv;
862 
863 	if ((b & sc->sc_stat) == TPM_STS_VALID) {
864 		/* Now wait for other flags. */
865 		b = b0 & ~TPM_STS_VALID;
866 		to++;
867 		goto again;
868 	}
869 
870 	if ((sc->sc_stat & b) != b) {
871 #ifdef TPM_DEBUG
872 		printf("tpm_waitfor: timeout: stat=%b b=%b\n",
873 		    sc->sc_stat, TPM_STS_BITS, b, TPM_STS_BITS);
874 #endif
875 		if (re-- && (b0 & TPM_STS_VALID)) {
876 			bus_space_write_1(sc->sc_bt, sc->sc_bh, TPM_STS,
877 			    TPM_STS_RESP_RETRY);
878 			goto restart;
879 		}
880 		return EIO;
881 	}
882 
883 	return 0;
884 }
885 
886 /* Start transaction. */
887 int
888 tpm_tis12_start(struct tpm_softc *sc, int flag)
889 {
890 	int rv;
891 
892 	if (flag == UIO_READ) {
893 		rv = tpm_waitfor(sc, TPM_STS_DATA_AVAIL | TPM_STS_VALID,
894 		    TPM_READ_TMO, sc->sc_read);
895 		return rv;
896 	}
897 
898 	/* Own our (0th) locality. */
899 	if ((rv = tpm_request_locality(sc, 0)) != 0)
900 		return rv;
901 
902 	sc->sc_stat = tpm_status(sc);
903 	if (sc->sc_stat & TPM_STS_CMD_READY) {
904 #ifdef TPM_DEBUG
905 		printf("tpm_tis12_start: UIO_WRITE status %b\n", sc->sc_stat,
906 		   TPM_STS_BITS);
907 #endif
908 		return 0;
909 	}
910 
911 #ifdef TPM_DEBUG
912 	printf("tpm_tis12_start: UIO_WRITE readying chip\n");
913 #endif
914 
915 	/* Abort previous and restart. */
916 	bus_space_write_1(sc->sc_bt, sc->sc_bh, TPM_STS, TPM_STS_CMD_READY);
917 	if ((rv = tpm_waitfor(sc, TPM_STS_CMD_READY, TPM_READY_TMO,
918 	    sc->sc_write))) {
919 #ifdef TPM_DEBUG
920 		printf("tpm_tis12_start: UIO_WRITE readying failed %d\n", rv);
921 #endif
922 		return rv;
923 	}
924 
925 #ifdef TPM_DEBUG
926 	printf("tpm_tis12_start: UIO_WRITE readying done\n");
927 #endif
928 
929 	return 0;
930 }
931 
932 int
933 tpm_tis12_read(struct tpm_softc *sc, void *buf, int len, size_t *count,
934     int flags)
935 {
936 	u_int8_t *p = buf;
937 	size_t cnt;
938 	int rv, n, bcnt;
939 
940 #ifdef TPM_DEBUG
941 	printf("tpm_tis12_read: len %d\n", len);
942 #endif
943 	cnt = 0;
944 	while (len > 0) {
945 		if ((rv = tpm_waitfor(sc, TPM_STS_DATA_AVAIL | TPM_STS_VALID,
946 		    TPM_READ_TMO, sc->sc_read)))
947 			return rv;
948 
949 		bcnt = tpm_getburst(sc);
950 		n = MIN(len, bcnt);
951 #ifdef TPM_DEBUG
952 		printf("tpm_tis12_read: fetching %d, burst is %d\n", n, bcnt);
953 #endif
954 		for (; n--; len--) {
955 			*p++ = bus_space_read_1(sc->sc_bt, sc->sc_bh, TPM_DATA);
956 			cnt++;
957 		}
958 
959 		if ((flags & TPM_PARAM_SIZE) == 0 && cnt >= 6)
960 			break;
961 	}
962 #ifdef TPM_DEBUG
963 	printf("tpm_tis12_read: read %zd bytes, len %d\n", cnt, len);
964 #endif
965 
966 	if (count)
967 		*count = cnt;
968 
969 	return 0;
970 }
971 
972 int
973 tpm_tis12_write(struct tpm_softc *sc, void *buf, int len)
974 {
975 	u_int8_t *p = buf;
976 	size_t cnt;
977 	int rv, r;
978 
979 #ifdef TPM_DEBUG
980 	printf("tpm_tis12_write: sc %p buf %p len %d\n", sc, buf, len);
981 #endif
982 
983 	if ((rv = tpm_request_locality(sc, 0)) != 0)
984 		return rv;
985 
986 	cnt = 0;
987 	while (cnt < len - 1) {
988 		for (r = tpm_getburst(sc); r > 0 && cnt < len - 1; r--) {
989 			bus_space_write_1(sc->sc_bt, sc->sc_bh, TPM_DATA, *p++);
990 			cnt++;
991 		}
992 		if ((rv = tpm_waitfor(sc, TPM_STS_VALID, TPM_READ_TMO, sc))) {
993 #ifdef TPM_DEBUG
994 			printf("tpm_tis12_write: failed burst rv %d\n", rv);
995 #endif
996 			return rv;
997 		}
998 		sc->sc_stat = tpm_status(sc);
999 		if (!(sc->sc_stat & TPM_STS_DATA_EXPECT)) {
1000 #ifdef TPM_DEBUG
1001 			printf("tpm_tis12_write: failed rv %d stat=%b\n", rv,
1002 			    sc->sc_stat, TPM_STS_BITS);
1003 #endif
1004 			return EIO;
1005 		}
1006 	}
1007 
1008 	bus_space_write_1(sc->sc_bt, sc->sc_bh, TPM_DATA, *p++);
1009 	cnt++;
1010 
1011 	if ((rv = tpm_waitfor(sc, TPM_STS_VALID, TPM_READ_TMO, sc))) {
1012 #ifdef TPM_DEBUG
1013 		printf("tpm_tis12_write: failed last byte rv %d\n", rv);
1014 #endif
1015 		return rv;
1016 	}
1017 	if ((sc->sc_stat & TPM_STS_DATA_EXPECT) != 0) {
1018 #ifdef TPM_DEBUG
1019 		printf("tpm_tis12_write: failed rv %d stat=%b\n", rv,
1020 		    sc->sc_stat, TPM_STS_BITS);
1021 #endif
1022 		return EIO;
1023 	}
1024 
1025 #ifdef TPM_DEBUG
1026 	printf("tpm_tis12_write: wrote %d byte\n", cnt);
1027 #endif
1028 
1029 	return 0;
1030 }
1031 
1032 /* Finish transaction. */
1033 int
1034 tpm_tis12_end(struct tpm_softc *sc, int flag, int err)
1035 {
1036 	int rv = 0;
1037 
1038 	if (flag == UIO_READ) {
1039 		if ((rv = tpm_waitfor(sc, TPM_STS_VALID, TPM_READ_TMO,
1040 		    sc->sc_read)))
1041 			return rv;
1042 
1043 		/* Still more data? */
1044 		sc->sc_stat = tpm_status(sc);
1045 		if (!err && ((sc->sc_stat & TPM_STS_DATA_AVAIL) == TPM_STS_DATA_AVAIL)) {
1046 #ifdef TPM_DEBUG
1047 			printf("tpm_tis12_end: read failed stat=%b\n",
1048 			    sc->sc_stat, TPM_STS_BITS);
1049 #endif
1050 			rv = EIO;
1051 		}
1052 
1053 		bus_space_write_1(sc->sc_bt, sc->sc_bh, TPM_STS,
1054 		    TPM_STS_CMD_READY);
1055 
1056 		/* Release our (0th) locality. */
1057 		bus_space_write_1(sc->sc_bt, sc->sc_bh,TPM_ACCESS,
1058 		    TPM_ACCESS_ACTIVE_LOCALITY);
1059 	} else {
1060 		/* Hungry for more? */
1061 		sc->sc_stat = tpm_status(sc);
1062 		if (!err && (sc->sc_stat & TPM_STS_DATA_EXPECT)) {
1063 #ifdef TPM_DEBUG
1064 			printf("tpm_tis12_end: write failed stat=%b\n",
1065 			    sc->sc_stat, TPM_STS_BITS);
1066 #endif
1067 			rv = EIO;
1068 		}
1069 
1070 		bus_space_write_1(sc->sc_bt, sc->sc_bh, TPM_STS,
1071 		    err ? TPM_STS_CMD_READY : TPM_STS_GO);
1072 	}
1073 
1074 	return rv;
1075 }
1076 
1077 #ifdef __FreeBSD__
1078 void
1079 #else
1080 int
1081 #endif
1082 tpm_intr(void *v)
1083 {
1084 	struct tpm_softc *sc = v;
1085 	u_int32_t r;
1086 #ifdef TPM_DEBUG
1087 	static int cnt = 0;
1088 #endif
1089 
1090 	r = bus_space_read_4(sc->sc_bt, sc->sc_bh, TPM_INT_STATUS);
1091 #ifdef TPM_DEBUG
1092 	if (r != 0)
1093 		printf("tpm_intr: int=%b (%d)\n", r, TPM_INTERRUPT_ENABLE_BITS,
1094 		    cnt);
1095 	else
1096 		cnt++;
1097 #endif
1098 	if (!(r & (TPM_CMD_READY_INT | TPM_LOCALITY_CHANGE_INT |
1099 	    TPM_STS_VALID_INT | TPM_DATA_AVAIL_INT)))
1100 #ifdef __FreeBSD__
1101 		return;
1102 #else
1103 		return 0;
1104 #endif
1105 	if (r & TPM_STS_VALID_INT)
1106 		wakeup(sc);
1107 
1108 	if (r & TPM_CMD_READY_INT)
1109 		wakeup(sc->sc_write);
1110 
1111 	if (r & TPM_DATA_AVAIL_INT)
1112 		wakeup(sc->sc_read);
1113 
1114 	if (r & TPM_LOCALITY_CHANGE_INT)
1115 		wakeup(sc->sc_init);
1116 
1117 	bus_space_write_4(sc->sc_bt, sc->sc_bh, TPM_INT_STATUS, r);
1118 
1119 #ifdef __FreeBSD__
1120 	return;
1121 #else
1122 	return 1;
1123 #endif
1124 }
1125 
1126 /* Read single byte using legacy interface. */
1127 static inline u_int8_t
1128 tpm_legacy_in(bus_space_tag_t iot, bus_space_handle_t ioh, int reg)
1129 {
1130 	bus_space_write_1(iot, ioh, 0, reg);
1131 	return bus_space_read_1(iot, ioh, 1);
1132 }
1133 
1134 #if 0
1135 /* Write single byte using legacy interface. */
1136 static inline void
1137 tpm_legacy_out(bus_space_tag_t iot, bus_space_handle_t ioh, int reg, u_int8_t v)
1138 {
1139 	bus_space_write_1(iot, ioh, 0, reg);
1140 	bus_space_write_1(iot, ioh, 1, v);
1141 }
1142 #endif
1143 
1144 /* Probe for TPM using legacy interface. */
1145 int
1146 tpm_legacy_probe(bus_space_tag_t iot, bus_addr_t iobase)
1147 {
1148 	bus_space_handle_t ioh;
1149 	u_int8_t r, v;
1150 	int i, rv = 0;
1151 	char id[8];
1152 
1153 	if (!tpm_enabled || iobase == -1)
1154 		return 0;
1155 
1156 	if (bus_space_map(iot, iobase, 2, 0, &ioh))
1157 		return 0;
1158 
1159 	v = bus_space_read_1(iot, ioh, 0);
1160 	if (v == 0xff) {
1161 		bus_space_unmap(iot, ioh, 2);
1162 		return 0;
1163 	}
1164 	r = bus_space_read_1(iot, ioh, 1);
1165 
1166 	for (i = sizeof(id); i--; )
1167 		id[i] = tpm_legacy_in(iot, ioh, TPM_ID + i);
1168 
1169 #ifdef TPM_DEBUG
1170 	printf("tpm_legacy_probe %.4s %d.%d.%d.%d\n",
1171 	    &id[4], id[0], id[1], id[2], id[3]);
1172 #endif
1173 	/*
1174 	 * The only chips using the legacy interface we are aware of are
1175 	 * by Atmel.  For other chips more signature would have to be added.
1176 	 */
1177 	if (!bcmp(&id[4], "ATML", 4))
1178 		rv = 1;
1179 
1180 	if (!rv) {
1181 		bus_space_write_1(iot, ioh, r, 1);
1182 		bus_space_write_1(iot, ioh, v, 0);
1183 	}
1184 	bus_space_unmap(iot, ioh, 2);
1185 
1186 	return rv;
1187 }
1188 
1189 /* Setup TPM using legacy interface. */
1190 int
1191 tpm_legacy_init(struct tpm_softc *sc, int irq, const char *name)
1192 {
1193 	char id[8];
1194 	u_int8_t ioh, iol;
1195 	int i;
1196 
1197 	if ((i = bus_space_map(sc->sc_batm, tpm_enabled, 2, 0, &sc->sc_bahm))) {
1198 		printf(": cannot map tpm registers (%d)\n", i);
1199 		tpm_enabled = 0;
1200 		return 1;
1201 	}
1202 
1203 	for (i = sizeof(id); i--; )
1204 		id[i] = tpm_legacy_in(sc->sc_bt, sc->sc_bh, TPM_ID + i);
1205 
1206 	printf(": %.4s %d.%d @0x%x\n", &id[4], id[0], id[1], tpm_enabled);
1207 	iol = tpm_enabled & 0xff;
1208 	ioh = tpm_enabled >> 16;
1209 	tpm_enabled = 0;
1210 
1211 	return 0;
1212 }
1213 
1214 /* Start transaction. */
1215 int
1216 tpm_legacy_start(struct tpm_softc *sc, int flag)
1217 {
1218 	struct timeval tv;
1219 	u_int8_t bits, r;
1220 	int to, rv;
1221 
1222 	bits = flag == UIO_READ ? TPM_LEGACY_DA : 0;
1223 	tv.tv_sec = TPM_LEGACY_TMO;
1224 	tv.tv_usec = 0;
1225 	to = tvtohz(&tv) / TPM_LEGACY_SLEEP;
1226 	while (((r = bus_space_read_1(sc->sc_batm, sc->sc_bahm, 1)) &
1227 	    (TPM_LEGACY_BUSY|bits)) != bits && to--) {
1228 		rv = tsleep(sc, PRIBIO | PCATCH, "legacy_tpm_start",
1229 		    TPM_LEGACY_SLEEP);
1230 		if (rv && rv != EWOULDBLOCK)
1231 			return rv;
1232 	}
1233 
1234 #if defined(TPM_DEBUG) && !defined(__FreeBSD__)
1235 	printf("%s: bits %b\n", sc->sc_dev.dv_xname, r, TPM_LEGACY_BITS);
1236 #endif
1237 	if ((r & (TPM_LEGACY_BUSY|bits)) != bits)
1238 		return EIO;
1239 
1240 	return 0;
1241 }
1242 
1243 int
1244 tpm_legacy_read(struct tpm_softc *sc, void *buf, int len, size_t *count,
1245     int flags)
1246 {
1247 	u_int8_t *p;
1248 	size_t cnt;
1249 	int to, rv;
1250 
1251 	cnt = rv = 0;
1252 	for (p = buf; !rv && len > 0; len--) {
1253 		for (to = 1000;
1254 		    !(bus_space_read_1(sc->sc_batm, sc->sc_bahm, 1) &
1255 		    TPM_LEGACY_DA); DELAY(1))
1256 			if (!to--)
1257 				return EIO;
1258 
1259 		DELAY(TPM_LEGACY_DELAY);
1260 		*p++ = bus_space_read_1(sc->sc_batm, sc->sc_bahm, 0);
1261 		cnt++;
1262 	}
1263 
1264 	*count = cnt;
1265 	return 0;
1266 }
1267 
1268 int
1269 tpm_legacy_write(struct tpm_softc *sc, void *buf, int len)
1270 {
1271 	u_int8_t *p;
1272 	int n;
1273 
1274 	for (p = buf, n = len; n--; DELAY(TPM_LEGACY_DELAY)) {
1275 		if (!n && len != TPM_BUFSIZ) {
1276 			bus_space_write_1(sc->sc_batm, sc->sc_bahm, 1,
1277 			    TPM_LEGACY_LAST);
1278 			DELAY(TPM_LEGACY_DELAY);
1279 		}
1280 		bus_space_write_1(sc->sc_batm, sc->sc_bahm, 0, *p++);
1281 	}
1282 
1283 	return 0;
1284 }
1285 
1286 /* Finish transaction. */
1287 int
1288 tpm_legacy_end(struct tpm_softc *sc, int flag, int rv)
1289 {
1290 	struct timeval tv;
1291 	u_int8_t r;
1292 	int to;
1293 
1294 	if (rv || flag == UIO_READ)
1295 		bus_space_write_1(sc->sc_batm, sc->sc_bahm, 1, TPM_LEGACY_ABRT);
1296 	else {
1297 		tv.tv_sec = TPM_LEGACY_TMO;
1298 		tv.tv_usec = 0;
1299 		to = tvtohz(&tv) / TPM_LEGACY_SLEEP;
1300 		while(((r = bus_space_read_1(sc->sc_batm, sc->sc_bahm, 1)) &
1301 		    TPM_LEGACY_BUSY) && to--) {
1302 			rv = tsleep(sc, PRIBIO | PCATCH, "legacy_tpm_end",
1303 			    TPM_LEGACY_SLEEP);
1304 			if (rv && rv != EWOULDBLOCK)
1305 				return rv;
1306 		}
1307 
1308 #if defined(TPM_DEBUG) && !defined(__FreeBSD__)
1309 		printf("%s: bits %b\n", sc->sc_dev.dv_xname, r, TPM_LEGACY_BITS);
1310 #endif
1311 		if (r & TPM_LEGACY_BUSY)
1312 			return EIO;
1313 
1314 		if (r & TPM_LEGACY_RE)
1315 			return EIO;	/* XXX Retry the loop? */
1316 	}
1317 
1318 	return rv;
1319 }
1320 
1321 int
1322 #ifdef __FreeBSD__
1323 tpmopen(struct cdev *dev, int flag, int mode, struct thread *td)
1324 #else
1325 tpmopen(dev_t dev, int flag, int mode, struct proc *p)
1326 #endif
1327 {
1328 	struct tpm_softc *sc = TPMSOFTC(dev);
1329 
1330 	if (!sc)
1331 		return ENXIO;
1332 
1333 	if (sc->sc_flags & TPM_OPEN)
1334 		return EBUSY;
1335 
1336 	sc->sc_flags |= TPM_OPEN;
1337 
1338 	return 0;
1339 }
1340 
1341 int
1342 #ifdef __FreeBSD__
1343 tpmclose(struct cdev *dev, int flag, int mode, struct thread *td)
1344 #else
1345 tpmclose(dev_t dev, int flag, int mode, struct proc *p)
1346 #endif
1347 {
1348 	struct tpm_softc *sc = TPMSOFTC(dev);
1349 
1350 	if (!sc)
1351 		return ENXIO;
1352 
1353 	if (!(sc->sc_flags & TPM_OPEN))
1354 		return EINVAL;
1355 
1356 	sc->sc_flags &= ~TPM_OPEN;
1357 
1358 	return 0;
1359 }
1360 
1361 int
1362 #ifdef __FreeBSD__
1363 tpmread(struct cdev *dev, struct uio *uio, int flags)
1364 #else
1365 tpmread(dev_t dev, struct uio *uio, int flags)
1366 #endif
1367 {
1368 	struct tpm_softc *sc = TPMSOFTC(dev);
1369 	u_int8_t buf[TPM_BUFSIZ], *p;
1370 	size_t cnt;
1371 	int n, len, rv, s;
1372 
1373 	if (!sc)
1374 		return ENXIO;
1375 
1376 	s = spltty();
1377 	if ((rv = (sc->sc_start)(sc, UIO_READ))) {
1378 		splx(s);
1379 		return rv;
1380 	}
1381 
1382 #ifdef TPM_DEBUG
1383 	printf("tpmread: getting header\n");
1384 #endif
1385 	if ((rv = (sc->sc_read)(sc, buf, TPM_HDRSIZE, &cnt, 0))) {
1386 		(sc->sc_end)(sc, UIO_READ, rv);
1387 		splx(s);
1388 		return rv;
1389 	}
1390 
1391 	len = (buf[2] << 24) | (buf[3] << 16) | (buf[4] << 8) | buf[5];
1392 #ifdef TPM_DEBUG
1393 	printf("tpmread: len %d, io count %d\n", len, uio->uio_resid);
1394 #endif
1395 	if (len > uio->uio_resid) {
1396 		rv = EIO;
1397 		(sc->sc_end)(sc, UIO_READ, rv);
1398 #ifdef TPM_DEBUG
1399 		printf("tpmread: bad residual io count 0x%x\n", uio->uio_resid);
1400 #endif
1401 		splx(s);
1402 		return rv;
1403 	}
1404 
1405 	/* Copy out header. */
1406 	if ((rv = uiomove((caddr_t)buf, cnt, uio))) {
1407 		(sc->sc_end)(sc, UIO_READ, rv);
1408 		splx(s);
1409 		return rv;
1410 	}
1411 
1412 	/* Get remaining part of the answer (if anything is left). */
1413 	for (len -= cnt, p = buf, n = sizeof(buf); len > 0; p = buf, len -= n,
1414 	    n = sizeof(buf)) {
1415 		n = MIN(n, len);
1416 #ifdef TPM_DEBUG
1417 		printf("tpmread: n %d len %d\n", n, len);
1418 #endif
1419 		if ((rv = (sc->sc_read)(sc, p, n, NULL, TPM_PARAM_SIZE))) {
1420 			(sc->sc_end)(sc, UIO_READ, rv);
1421 			splx(s);
1422 			return rv;
1423 		}
1424 		p += n;
1425 		if ((rv = uiomove((caddr_t)buf, p - buf, uio))) {
1426 			(sc->sc_end)(sc, UIO_READ, rv);
1427 			splx(s);
1428 			return rv;
1429 		}
1430 	}
1431 
1432 	rv = (sc->sc_end)(sc, UIO_READ, rv);
1433 	splx(s);
1434 	return rv;
1435 }
1436 
1437 int
1438 #ifdef __FreeBSD__
1439 tpmwrite(struct cdev *dev, struct uio *uio, int flags)
1440 #else
1441 tpmwrite(dev_t dev, struct uio *uio, int flags)
1442 #endif
1443 {
1444 	struct tpm_softc *sc = TPMSOFTC(dev);
1445 	u_int8_t buf[TPM_BUFSIZ];
1446 	int n, rv, s;
1447 
1448 	if (!sc)
1449 		return ENXIO;
1450 
1451 	s = spltty();
1452 
1453 #ifdef TPM_DEBUG
1454 	printf("tpmwrite: io count %d\n", uio->uio_resid);
1455 #endif
1456 
1457 	n = MIN(sizeof(buf), uio->uio_resid);
1458 	if ((rv = uiomove((caddr_t)buf, n, uio))) {
1459 		splx(s);
1460 		return rv;
1461 	}
1462 
1463 	if ((rv = (sc->sc_start)(sc, UIO_WRITE))) {
1464 		splx(s);
1465 		return rv;
1466 	}
1467 
1468 	if ((rv = (sc->sc_write(sc, buf, n)))) {
1469 		splx(s);
1470 		return rv;
1471 	}
1472 
1473 	rv = (sc->sc_end)(sc, UIO_WRITE, rv);
1474 	splx(s);
1475 	return rv;
1476 }
1477 
1478 int
1479 #ifdef __FreeBSD__
1480 tpmioctl(struct cdev *dev, u_long cmd, caddr_t data, int flags,
1481     struct thread *td)
1482 #else
1483 tpmioctl(dev_t dev, u_long cmd, caddr_t data, int flags, struct proc *p)
1484 #endif
1485 {
1486 	return ENOTTY;
1487 }
1488